Mortars are mixtures of one or more air or hydraulic binders, aggregates, water, and chemical or mineral additives. Mortars are most often used for plastering or masonry.
Masonry mortars are a mixture of a binder (common lime, hydraulic lime, cement, ash) and an additive (sand), which, when mixed with water, form a plastic slurry that hardens over time.
The mortars bond the individual elements of the masonry (bricks, stones, blocks), filling the joints between them. They level out irregularities, thus helping to transmit stresses more evenly.
It is necessary for the mortars to possess important qualities such as mobility, resistance to delamination, compactness, and after hardening - sufficient strength.
TYPES OF SOLUTIONS
Depending on the type of binder, mortars are: lime, cement, lime-cement, cement-lime, clay, gypsum, and fly ash mortar.
- Cementitious: when the binder is cement;
- Lime: when the binder is lime;
- Cement-lime: when the solution has a lime content of no more than 50% of the total amount of the binder;
- Lime-cement: when the solution has a cement content of no more than 50% of the total amount of the binder.
Lime and lime-cement mortars are used for masonry. These are the most commonly used mortars. Before masonry, the bricks must be wetted to absorb the moisture of the mortar. For areas that are more heavily loaded or exposed to moisture, cement mortars are used. Clay mortars are poorly resistant to weathering and are usually used in adobe masonry.
WIENERBERGER OFFERS TWO SPECIALIZED SOLUTIONS
In order to use the qualities of ceramic blocks most effectively, it is of particular importance that they are laid with a mortar specially developed for this purpose. Such a requirement is actually typical of all high-tech products that have entered construction practice. They have significantly changed classical technologies and imposed the requirement to work with a system of materials developed by the same manufacturer or explicitly recommended by him. Classical lime-cement mortars are still widely used, but new masonry materials require specially created masonry mortars and adhesives for them. New masonry materials contain special ingredients, a product of modern construction chemistry, which give them properties unattainable for classical materials. Two of the products of the renowned brand in the industry WIENERBERGER, which are offered by us, are exactly such. These are POROTHERM TM - a specially created thermal mortar for laying POROTHERM 38 N+F Hi blocks and FORATI Fix, intended for laying FORATI bricks. The emergence of the two specialized solutions will undoubtedly give an even stronger impetus to the application of these high-tech building materials in construction practice in our country. And since these two products have entered construction en masse, we will dwell on them in more detail.
WHY CHOOSE POROTHERM TM?
The excellent thermal insulation properties of POROTHERM 38 N+F Hi blocks are due both to their multi-chamber structure with numerous vertical cavities of small cross-section, as well as to the fine porous structure of their walls, obtained using a special technology in the clay firing process.
A significant reduction in heat loss through the wall is only possible when its airtightness is guaranteed. POROTHERM 38 N+F Hi blocks help to easily achieve this requirement. Thanks to their precise dimensions, their ends fit tightly together, and their shape with a tongue and groove relief provides the necessary sealing against air leakage through the wall. It remains to ensure reliable sealing of the joints between the rows, which largely depends on the qualities of the masonry mortar used. When aiming to reduce heat loss as much as possible in walls with POROTHERM 38 N+F Hi blocks, the only weak point through which, figuratively speaking, heat can “leak” more easily into the surrounding space remains precisely the horizontal joints between the rows, formed by the masonry mortar. In classic lime-cement masonry mortars, sand obtained from nature is used as a filler, which in itself is a very good conductor of heat. This also applies to hardened cement. For this reason, the use of such a solution will create a network of multiple thermal bridges. Now there is a suitable masonry mortar - POROTHERM TM, with which thermal bridges are avoided when laying POROTHERM 38 N+F Hi blocks. This is due to its thermal conductivity, which closely approaches the thermal conductivity of the building material.
Since the blocks are laid so that their cavities are in a vertical position, the mortar must have the ability to adhere well to the ceramics and not fall into the cavities. This would worsen the thermal insulation ability of the wall, reduce the strength of the connection between the rows and cause excessive mortar consumption.
These, as well as a number of other requirements, are met by the new specialized thermal mortar for masonry POROTHERM TM. Its thermal conductivity coefficient is λ=0.19 W/mK, while for the classic lime-cement mortar with ordinary sand this coefficient is 0.7–0.8 W/mK. This low value was achieved by using a lightweight material – swollen perlite sand with a grain size of up to 2 mm – instead of sand obtained from nature as a filler. The low thermal conductivity of the hardened masonry mortar is naturally also associated with its low bulk density – about 650 kg/cubic m.
POROTHERM TM is sold as a dry mix, packed in bags weighing about 20 kg, which produces about 40 l of masonry mortar, sufficient for the construction of about 0.8 cubic meters of masonry. It is prepared by mixing one bag of dry mix with 13–14 l of water. Since perlite grains have a low compressive strength, in order not to crush and grind into powder, the mortar should be mixed with a gravity or continuous flow mixer for about 4–5 minutes. The fresh mortar prepared in this way is suitable for use within 1–2 hours. Successful masonry depends to a large extent on the consistency of the mortar, i.e. on its density. It should be such that, when applied in an evenly thick layer over the entire surface of the row of bricks, it penetrates the holes in the bricks to a depth of about 0.5 cm. This achieves the necessary bond strength with optimal material consumption and without the risk of deterioration of the thermal insulation properties of the blocks due to partial filling of their cavities. The mortar is applied at a layer thickness of about 12 mm. No mortar is placed along the vertical joint between the faces of every two adjacent blocks in the row. This need is eliminated due to the reasons already mentioned – the precise dimensions and the design of the faces with a tongue and groove profile.
When working with POROTHERM blocks, the placement of the first row of blocks is of great importance for the correct laying of the masonry. For this, a base layer is made, which is leveled horizontally and aligned at a minimum thickness of 1 cm. It also levels out any irregularities on the concrete base. After waiting until it gains sufficient strength, the blocks in the first row are arranged. If there is a possibility of capillary moisture penetrating through the base, horizontal waterproofing is performed under the base leveling layer.
Before masonry, especially during the hot summer months, it is a good idea to wet the ceramic blocks with water so that they do not vigorously absorb moisture from the masonry mortar.
WHY CHOOSE FORATI Fix?
The mortar for masonry, or more precisely the FORATI Fix adhesive, is specially developed for masonry of FORATI horizontally perforated ceramic bricks. These bricks are well known in Bulgaria with their traditional format and are used for building non-load-bearing walls, being laid so that the cavities are located horizontally. The correct shape and flat surface of the brick walls allow them to be glued with a thin layer of adhesive, which is actually the FORATI Fix mortar.
The adhesive is supplied as a dry, factory-prepared mixture of cement, fine sand with a grain size of up to 0.6 mm and special additives. The solution is prepared before use by stirring with an electric mixer by adding 5.5–6.0 l of water per bag weighing 25 kg of dry material. Mixing is carried out twice with an intermediate waiting time of 5–10 min., necessary for the solution to mature. For FORATI 4 bricks (250x250x120 mm) the solution consumption rate is about 40 kg/cubic m. When laying with FORATI 8 bricks (330x250x200 mm) this rate is about 25 kg/cubic m.
The freshly prepared mortar should be used within 3–4 hours. It is applied using a notched steel trowel with a tooth size of 10x10 mm. The evenly thick layer of adhesive should cover the entire area of the row of bricks. Adhesive mortar is also applied to one vertical face of each brick to ensure the airtightness of the masonry.
WIENERBERGER's complete wall system solutions make masonry work as easy as possible and guarantee exceptional quality of execution. The use of ready-made mortars, prepared in factory conditions, guarantees easy logistics, low transport and on-site costs, accurate dosing on site and consistent quality.
WHAT DO WE OFFER?
With us you can find modern modifications of the classic lime-cement mortars, adhesive mixture for masonry of any size of aerated concrete blocks and specialized WIENERBERGER mortars, about which we have informed you in detail. However, it will not be superfluous to introduce you to their descriptions on the website of the Bulgarian representative office of the renowned Austrian company in the industry. Here is what the specialists write:
FORATI Fix is a factory-made dry mix consisting of cement, sand and additives and is specially developed for bonding ceramic bricks with horizontal cavities Forati. The material has a fine grain size of 0.6 mm and requires a thin layer application on the contact surface.
It is available in 25 kg bags. The consumption when laying Forati 4 bricks /25x25x12 cm/ is about 40 kg per 1 cubic meter of masonry, and when laying Forati 8 bricks /33x25x20 cm/ the consumption is about 25 kg per 1 cubic meter. To one bag of Forati Fix solution (25 kg) is added about 5.5 - 6.0 liters of water. When mixing, be careful not to introduce air into the solution. A residence time of 5 - 10 minutes is recommended for maturation, then mix again and add water if necessary.
The solution has a suitable consistency when, when applied with a notched trowel (trowel) on a ceramic brick, visible grooves from the teeth remain. It is applied using the thin-layer method, with a comb over the entire plane of the contact surface and with the required thickness. The correction time is about 10–15 minutes. The use time of the finished mixture is 3–4 hours, depending on atmospheric conditions.
POROTHERM TM - thermal mortar for single-layer masonry with increased thermal insulation properties. POROTHERM TM is a special factory-prepared masonry mortar from WIENERBERGER, developed for single-layer brick walls with high thermal insulation properties POROTHERM 38 N+F Comfort. The dry mixture contains perlite and has an extremely low thermal conductivity coefficient. It is applied with a layer thickness as with normal masonry mortar (about 8-12 mm), but without impairing the thermal insulation characteristics of the entire wall.
POROTHERM TM is extremely light - in a dry state the bulk density is about 650 kg/cubic meter. It is supplied as a dry mixture in bags weighing 20 kg (40 l of solution). With the addition of about 13–14 liters of clean water and a mixing time of about 4 - 5 minutes, about 40 liters of ready-made solution are obtained from one bag. The consumption of POROTHERM TM when using Porotherm 38 N+F Comfort is about 70 liters of ready-made solution for 1 cubic meter of finished wall. Particular attention should be paid to the preparation of the solution.
Since it contains perlite, the mortar should be mixed only in a gravity mixer. The fresh mortar should be laid, depending on the weather conditions, within 1 -2 hours. The temperature of the air, the base and the material should be above +5°C during laying, as well as during bonding. The optimal consistency of the mortar is selected so that it enters the cavities of the bricks of the lower row to a depth of no more than 0.5 cm. This depth of penetration ensures better adhesion between the mortar and the bricks, which provides greater strength of the masonry.
In order to guarantee the thermal insulation capacity and the strength of the wall, it is important that the mortar is applied to the entire area of the brick along the horizontal joints. The special tongue and groove assembly of this type of brick eliminates the need to apply mortar to the vertical joints, which increases the speed of construction, the straightness of the finished wall, and reduces the consumption of mortar per cubic meter of masonry compared to traditionally used bricks.
More detailed information about lime-cement mortars and aerated concrete adhesive can be found in their personal technical data sheets.
The mortars are from the brands WEBER, BAUMIT, WIENERBERGER, YTONG.
The prices are affordable.
